P11221 - Noise Reduction for
Internal Combustion Engines
Team Leader: Christopher Morehouse
Mechanical Engineers: - Julie Maier
- Caroline Bills
- Ted Zachwieja
Faculty Advisor:
Ed Hanzlik
Customer:
Dr. Alan Nye
Agenda
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Problem Overview
Project Objectives
Customers and Users
Project Flow Chart & Plan
Engine Model Overview
Design Options
Design Feasibility
Next Steps
Questions & Discussions
Background
• Noise abatement - growing field
• Formula SAE Sound Constraints
• Conventional Methods Reduce
Performance
• No RIT Background in this Field
• Multiple Applications Possible
• Customer:
• Users:
Dr. Nye
Formula SAE Team
EE 2010-2 Team
Project Scope
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Investigate physics of sound generation and transmission
Identify and locate major noise contributors in ICE
Analyze and model noise generation of ICE
Propose design for noise reduction mechanism
Provide background to EE team for parallel ANC project
Provide noise reduction demonstrator for Spring 2011
ImagineRIT
Project Deliverables
• Engine Sound Model
• ANC System Constraints
• Demonstrator for ImagineRIT
Project Overview
Project Breakdown
Research
Topics
Electrical
(ANC)
NOISE
REDUCTION
Analyze
SAE Engine
Mechanical
Proposals
Detailed Project Breakdown
Packaging
& Layout
Research
Topics
Specs &
Documents
Sound
Electrical
(ANC)
NOISE
REDUCTION
Sound
Generation
Mechanical
Proposals
Analyze
SAE Engine
Passive
Active
Gather Data
(Engine Characterization)
Resonator
Absorptive
Resonator
Internal
Combustion
Engine
Current
Muffler/Exhaust
Systems
Customer Needs
Engineering Specifications
Relationship Diagram
•ES 1
Reduce noise level
•ES 4
Passes B10.2.1 of the SAE Formula rules
•ES 7
Component Costs
•ES 12 Change in Engine Max Power
The Plan
ID
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Task Name
Project Planning
Obtain Customer Needs (continuous)
Define Engineering Specifications
Create Preliminary Plan
Define Possible Risks (preliminary)
Create / Define Team Norms & Values
Choose Team Leader
Benchmarking / Research
Physics of Sound
Sound Measurement
Internal Combustion Engine
Current Noise Reduction Methods
Concept Generation (Noise Reduction)
Contact Acoustics Experts (D-R & Dr. Wyffels)
Validate Assumptions
Become Familiar with Sound in Mufflers
Research Absorption Materials - Muffler Design
Research Anti-Phase Design
Create List of Design Options
System Analysis
Feasibility Study of Available Designs
Risk Assessment - Updated
Obtain Actual Sound Exhaust Recording & Measurements
Create Visual Aids - Exhaust System Layout (black boxes)
Compile Presentation & Practice
Perform System Level Design Review
Duration
Start
Finish
15 days
8 days
8 days
1 day
1 day
1 day
1 day
7 days
7 days
7 days
7 days
7 days
10 days
2 days
2 days
12 days
2 days
7 days
4 days
5 days
3 days
1 day
2 days
1 day
2 day
1 day
Fri 9/10/10
Fri 9/10/10
Fri 9/17/10
Thu 9/23/10
Thu 9/23/10
Thu 9/23/10
Thu 9/23/10
Fri 9/10/10
Fri 9/10/10
Fri 9/10/10
Fri 9/10/10
Fri 9/10/10
Fri 9/24/10
Mon 9/27/10
Mon 10/4/10
Fri 9/24/10
Wed 9/29/10
Fri 9/24/10
Fri 10/1/10
Mon 10/4/10
Mon 10/4/10
Wed 10/6/10
Mon 10/4/10
Wed 10/6/10
Wed 10/6/10
Fri 10/8/10
Fri 9/24/10
Fri 9/17/10
Fri 9/24/10
Thu 9/23/10
Thu 9/23/10
Thu 9/23/10
Thu 9/23/10
Thu 9/16/10
Thu 9/16/10
Thu 9/16/10
Thu 9/16/10
Thu 9/16/10
Tue 10/5/10
Tue 9/28/10
Tue 10/5/10
Tue 10/5/10
Thu 9/30/10
Thu 9/30/10
Mon 10/4/10
Fri 10/8/10
Wed 10/6/10
Thu 10/7/10
Tue 10/5/10
Wed 10/6/10
Thu 10/7/10
Fri 10/8/10
September
10 17 24
x x x
x x
x x
x
x
x
x
x x
x x
x x
x x
x x
x
x
x
x
x
x
Concrete Date
Topic
Task
complete task
1
October
8 15 22 29
x
x
x
x
x
x
x
x
x
x
The Plan
ID
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Task Name
Engine Characterization
Define Process & Inputs
Look at Current Formula car
Determine Sensors & Equipment need
Acquire Sensors & Other Equipment (if needed)
Set-up Formula Car for Testing
Obtain Data from Formula Car
Analyze Data - Create "Map" of engine
Detailed Design Analysis
Update Risk Assessment
Develop Best Mechancial Option(s)
Develop System Layout (Anti-Phase Design)
Develop Packaging (Anti-Phase Design)
Final Design Analysis
Update Risk Assessment
Formalize Engine Characterization results
Compile Data & Information for EE's
Perform Detailed Design Review
Project Review
Perform Project Review
Complete & upload all documentation on EDGE
MSD II Preparation / Planning
Order materials and parts needed
Create Specification Sheet and Summary for EE's
Create WBS and Plan / Schedule
x
Duration
Start
Finish
7 days
2 day
1 day
1 day
5 days
1 day
1 day
2 days
28 days
1 day
28 days
28 days
28 days
7 days
1 day
2 days
2 days
1 day
1 day
1 day
3 days
7 days
2.5 mo
2 days
6 days
Mon 10/4/10
Mon 10/4/10
Fri 10/8/10
Tue 10/5/10
Tue 10/5/10
Thu 10/14/10
Thu 10/14/10
Thu 10/14/10
Sat 10/9/10
Sat 10/9/10
Sat 10/9/10
Sat 10/9/10
Sat 10/9/10
Wed 11/3/10
Thu 11/4/10
Wed 11/3/10
Wed 11/3/10
Fri 11/5/10
TBD
TBD
Mon 11/15/10
Mon 11/15/10
Mon 11/15/10
Tue 11/16/10
Fri 11/12/10
Thu 10/14/10
Tue 10/5/10
Fri 10/8/10
Tue 10/5/10
Sat 10/9/10
Thu 10/14/10
Thu 10/14/10
Fri 10/15/10
Thu 11/4/10
Sat 10/9/10
Thu 11/4/10
Thu 11/4/10
Thu 11/4/10
Thu 11/4/10
Thu 11/4/10
Thu 11/4/10
Thu 11/4/10
Fri 11/5/10
TBD
TBD
Wed 11/17/10
Wed 11/17/10
Mon 2/28/11
Wed 11/17/10
Wed 11/17/10
September
10 17 24
1
Concrete Date
Topic
Task
complete task
October
8 15 22 29
x
x
x
November
5 12 19
Risk Assessment
Risk Assessment
Risk Assessment
Research & Benchmarking
Sound is Pressure
http://www.school-forchampions.com/science/noise_cancellation.htm
How We Measure Sound
• Digital Signal
Processing
• Decibel Meters
• Sound Pressure
Indicators
IC Engine Sources
Pressure Waves
Engine Model
MECHANICAL DESIGN
OPTIONS
Current Design
• Glass Pack
• Low Flow
Restriction
• Low Noise
Attenuation
Unpacked Concentric Tube
Resonators
• Design #1: Single-pass
• Design #2: Multi-pass
• Passive
http://www.eastsidemufflers.com/mufflers.htm
Design #1: Single-pass
Resonating
Chamber
Inner Pipe
Exhaust Gas
Flow
Sound Waves
Holes in pipe
Design #2:
Multi-pass
Exhaust Gas
Flow
Resonating Chamber
Exhaust Gas
Flow
Packed Concentric Tubes
• Design #3: Metal Foam
• Design #4: Full Length of the Exhaust System
• Design #5: Rock Wool and Stainless Steel Wool
www.stainlessworks.net
Designs #3 & #4: Metal Foams
www.bundesregierung.de
Foams
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Permeability
Pore Size
Level of Reticulation
Absorption Area
– Length
– Curves
• Thickness
• Scott Acoustical Laboratories
Foams
www.bundesregierung.de
Optimal Foam Structure
Industrial Noise Control Handbook.
Cheremisinoff and Cheremisinoff
Absorption Area
Industrial Noise Control Handbook.
Cheremisinoff and Cheremisinoff
Metal Foams
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Available in a variety of densities
Available in a variety of pore sizes
ERG Duocel
Test kit en route
– Aluminum
– Copper
– Silicon Carbide
– Reticulated Vitreous Carbon (RVC)
ERG Duocel Metal Foams
ERGaerospace.com
Design #5: Rock Wool
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A fibrous insulation made from basalt
Custom Muffler and Auto Repair, LA
Cone Engineering, Inc., CA
MagnaFlow Exhaust
Rock Wool
Design #7: Exhaust Silencer Insert
• Applied to exhaust tip
• Reflects Sound Waves
back into exhaust
stream
Design #8: Active Single-pass
Moves laterally
Frequency Data
Exhaust Gas
Flow
Resonating Chamber
Design #9: Active Multi-pass
Moves laterally
Frequency Data
Resonating Chamber
Exhaust Gas
Flow
ELECTRICAL DESIGN
OPTION
Design #10:
Active Noise Cancellation (ANC)
This generates more sound by
the adding of two waves.
ANC continued
Introducing a wave 180 degrees
out of phase of the targeted noise
being cancelled.
How ANC Applies to Cars
Three Major components of sound generation occur in a car
Dominating noise comes from the muffler
Feed Forward Control
Feedback Control
http://focus.ti.com.cn/cn/lit/an/spra042/spra042.pdf
Installation Options
CONCEPT SELECTION
List of Design Options
• Current Glass Pack*
1. Unpacked Concentric Tube Resonator
2. Multi-pass Resonator
3. Metal Foam*
4. Entire Length of Exhaust System Wrapped
5. Lava Rock/Rockwool and Stainless Steel Wool*
6. Multiple Exhaust Pipes (Combination)
7. End Cap Silencer (Combination)
8. ANC
9. Variable Length Resonator - Single Pass
10. Variable Length Resonator - Multiple Pass
Criterion List
Criteria
Importance Importance (%)
Ease of Manufacture
1
3%
Ease of Application
1
3%
Noise Reduction
9
30%
Power Usage
3
10%
System Life
1
3%
Weight
3
10%
Cost
3
10%
Effect on Back Pressure
9
30%
Simple Concept Matrix
Simple Concept Matrix (cont.)
Simple Concept Matrix (cont.)
Weighted Concept Screening
Matrix
Weighted Concept Screening
Matrix
Weighted Concept Screening
Matrix
Results
#
0
1
2
3
4
5
6
7
8
9
10
Design
Current Glass Pack*
Unpacked Concentric Tube Resonator
Multipass Resonator
Metal Foam*
Entire Length of Exhaust System Wrapped
Multiple Exhaust Pipes (Combination)
End Cap Silencer (Combination)
ANC
Variable Length Resonator - Single Pass
Variable Length Resonator - Multiple Pass
Lava Rock/Rockwool and Stainless Steel Wool*
Score Score - Expert Score w/o Noise Continue?
0
0
0
NO
1.23
0.63
0.48
YES
1.40
-0.40
-1.86
NO
0.43
-0.67
YES
0.17
2.27
-1.05
NO
0.23
0.23
-0.95
1.30
1.43
-0.70
-2.50
-4.86
YES
1.77
0.27
-1.33
YES
0.67
-1.13
-2.90
NO
0.70
-0.29
YES
Resulting Design Options
• Unpacked Concentric Tube Resonator
• Packed Concentric Tube:
– Metal Foam
– Lava Rock/Rockwool and Stainless Steel
Wool
• Variable Length Resonator - Single Pass
• ANC
(End Cap Silencer, Multiple Exhaust Pipes)
Critical Action Items
Action Item
•Design Commitment
•Data Collection (CB)
•Engine Model (CM)
•Design Resonator (JM)
•Detailed BOM & Budget (CB)
•Detailed ANC Component
Requirements (TZ)
•Detailed ANC Layout
& Mounting Schematic (TZ)
Goal
Oct. 14
Oct. 18
Oct. 22
No Later Than
Oct. 15
Oct. 21
Oct. 25
Oct. 25
Oct. 29
Oct. 22
Oct. 29
Oct. 29
Nov. 1
Sources
• http://www.eastsidemufflers.com/mufflers.htm
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Picture Sources
Slide 1
http://www.motorcycle-usa.com/photogallerys/03CBR600RReuro_DetG.jpgSlide2
Slide 2
http://www.emspowered.com/
http://www.motorcycle.com/manufacturer/honda/2003-cbr-600-track-test-1225.html
Slide 5
http://www.impactlab.net/2010/07/01/new-drug-could-reverse-hearing-loss-caused-by-loud-noises/
Slide 35
http://www.dirtwerkz.com/images/products/dbdawg/db-Dawg_Black_450.jpg